Conventionally, there has been a refrigeration device which, like the one described in JP-A No. 2013-224785, is equipped with a refrigerant jacket that uses refrigerant flowing through a refrigerant circuit to cool cooled elements. In this refrigeration device, a high-voltage electrical parts group and a low-voltage electrical parts group are mounted on a main surface of a printed wiring board, and the refrigerant jacket is placed in such away that it can cool the cooled elements of the high-voltage electrical parts group. Furthermore, from the standpoint of simplifying the wiring pattern, a reactor is connected via a harness rather than being mounted on the main surface of the printed wiring board.